This community-based participatory research project investigates exposures to two classes of emerging endocrine-disrupting chemicals (EDCs) with the Yupik people of St. Lawrence Island (SLI) in the Alaskan Arctic. The Arctic acts as a "cold trap" and is a hemispheric sink for persistent organic pollutants (POPs) that are transported through a well-documented process known as global distillation via prevailing atmospheric and oceanic currents from warmer regions. The Arctic is significant as an indicator region for long-range transport of legacy chemicals-a term applied to those POPs that have been banned or restricted-as well as emerging chemicals of concern. Arctic wildlife and people are also exposed to high levels of POPs from local sources, such as military toxics, solid waste dumps, and household dust. Exposure to POPs from both distant and local sources is a trend in the Arctic that is likely to increase due to increased global use and production of EDCs and climate warming. The purpose of this project is to initiate research partnerships that work in collaboration with the two Yupik villages of SLI to assess multiple exposure routes of two emerging EDCs-polybrominated diphenyl ethers (PBDEs) and perfluorinated compounds (PFCs). The project will assess exposures to PBDEs and PFCs in surface waters through analyses of contaminant levels and biomarkers for xenobiotic chemicals in the threespine stickleback fish. The research team will also analyze household dust for PBDEs and PFCs. Because the Yupik people of SLI depend on the harvest of wild foods to sustain them and their way of life, the research team will analyze levels of PBDEs and PFCs in traditional foods which are likely a major exposure pathway due to the biomagnification of POPs in marine mammals and fish that are critical components of the Yupik diet. This study will include a human biomonitoring component in order to assess levels of PBDEs and PFCs in human blood serum in relation to measures of thyroid health. The aim of this exposure assessment is to provide information, ownership of data, and training for the people of SLI so that they can plan and participate in public health actions to reduce environmental health risks. Finally, the research team collaborates with the leadership, elders, and youth of SLI to develop measures to prevent and mitigate environmental exposures through community educational programs and public policy actions, including community-based research institutes for college credit, health fairs for all community members, and workshops for health care providers. PUBLIC HEALTH RELEVANCE: Exposures to endocrine-disrupting substances (such as flame retardants and other industrial chemicals) that are found in our environment, food, and consumer goods are linked in animal and human studies with a wide range of diseases that may affect human reproductive and thyroid health, the normal development of children, and the health of future generations. Arctic Indigenous peoples have some of the highest exposure to persistent chemicals of any population on earth, even though these chemicals have never been produced in the Arctic. This project is relevant to public health because it: 1) assesses ways that the Yupik people of St. Lawrence Island in Arctic Alaska might be exposed to harmful endocrine-disrupting chemicals in water, traditional foods, and their homes;and 2) develops ways to prevent diseases that could serve as a model for other Arctic communities.